feat(classes): add ClassesController with operation logging and permission guards

apps/server/src/classes/classes.module.ts

@@ -2,10 +2,12 @@ import { Module } from '@nestjs/common';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { Class, ClassStudent, ClassTeacher } from '../entities';
 import { ClassesService } from './classes.service';
+import { ClassesController } from './classes.controller';
 import { OperationLogsModule } from '../operation-logs/operation-logs.module';
 
 @Module({
   imports: [TypeOrmModule.forFeature([Class, ClassStudent, ClassTeacher]), OperationLogsModule],
+  controllers: [ClassesController],
   providers: [ClassesService],
   exports: [ClassesService],
 })